Adult Stature Research Articles

Functional traits as predictors of vital rates across the life cycle of tropical trees

SummaryThe ‘functional traits’ of species have been heralded as promising predictors for species’ demographic rates and life history. Multiple studies have linked plant species’ demographic rates to commonly measured traits. However, predictive power is usually low – raising questions about the practical usefulness of traits – and analyses have been limited to size‐independent univariate approaches restricted to a particular life stage.Here we directly evaluated the predictive power of multiple traits simultaneously across the entire life cycle of 136 tropical tree species from centralPanama. Using a model‐averaging approach, we related wood density, seed mass, leaf mass per area and adult stature (maximum diameter) to onset of reproduction, seed production, seedling establishment, and growth and survival at seedling, sapling and adult stages.Three of the four traits analysed here (wood density, seed mass and adult stature) typically explained 20–60% of interspecific variation at a given vital rate and life stage. There were strong shifts in the importance of different traits throughout the life cycle of trees, with seed mass and adult stature being most important early in life, and wood density becoming most important after establishment. Every trait had opposing effects on different vital rates or at different life stages; for example, seed mass was associated with higher seedling establishment and lower initial survival, wood density with higher survival and lower growth, and adult stature with decreased juvenile but increased adult growth and survival.Forest dynamics are driven by the combined effects of all demographic processes across the full life cycle. Application of a multitrait and full‐life cycle approach revealed the full role of key traits, and illuminated how trait effects on demography change through the life cycle. The effects of traits on one life stage or vital rate were sometimes offset by opposing effects at another stage, revealing the danger of drawing broad conclusions about functional trait–demography relationships from analysis of a single life stage or vital rate. Robust ecological and evolutionary conclusions about the roles of functional traits rely on an understanding of the relationships of traits to vital rates across all life stages.

An exploration of interpersonal violence among Holocene foragers of Southern Africa

A common assertion that humans are inherently aggressive toward one another is based in part on interpretation of anthropological evidence, including observational reports of Khoesan immediate-return hunter-gatherers of southern Africa. Bioarchaeological evidence from 446 dated South African Cape Holocene skeletons representing Khoesan ancestors provides an opportunity to review approaches to interpersonal conflict over thousands of years. A synthesis of paleodemographic and skeletal information suggests a complex picture. The pattern noted among descendant Khoesan groups of male killings via poison arrows is not discernable in ancestral demography. Published reports of healed cranial trauma are not geographically localized; most are adult men, and some can be parsimoniously explained as the outcomes of accidents. Skeletons with unhealed perimortem lesions are limited to the southwestern region, at dates around 2500 years ago; most are women and children. The perimortem skeletal trauma is contemporaneous with a period during which a transitory decline in adult stature occurs throughout the Cape but not in the region with the apparent violence. This suggests a novel, transient social pattern in that community. In sum, the disparate patterns of antemortem and perimortem trauma among these Holocene foragers support a narrative that emphasizes the situational nature, and the general rarity, of interpersonal violence.

Architecture of four tree species from different strata of a semideciduous forest in southern Brazil

The present study was conducted in a semideciduous Brazilian forest to verify whether there were architectural differences during development among tree species that differ in adult stature, such that understorey species maximise light interception and canopy and emergent species maximise height gain to rapidly reach high light environments. The crown illumination index and light interception index of individual trees as well as the variation in form among the understorey species were also analysed. Two understorey, one canopy and one emergent species were chosen, and the individuals were divided into height classes. Architectural comparisons among individuals were evaluated using allometry; crown illumination and light interception indices were compared among species. All comparisons were made within each height class. The two understorey species presented some differences in growth form, but both exhibited greater investment in the crown than did the canopy and emergent species. The crown illumination index did not differ among species, but the light interception index was higher for the understorey species. The results indicated that architectural differences between the studied species arise predominantly because species belong to different strata of the forest. Comparison within height classes was important because it allowed us to evaluate species architectural characteristics throughout plant development that cannot be detected using a single height-class comparison or that can be neglected if individuals of different heights are compared.

Protein and Micronutrient Intakes Are Associated with Child Growth and Morbidity from Infancy to Adulthood in the Philippines

Background: Interactions between nutrition and infections in developing countries are complex, and analyses of the interrelations require data from longitudinal studies that span several years and a comprehensive framework facilitating the formulation of food and health policies.Objective: The effects of dietary intakes in the Philippines for birth outcomes, heights, weights, and morbidity during ages 2–24 mo; heights and weights during ages 8–19 y; and completed adult heights were analyzed.Methods: Data on >3000 children from the Cebu Longitudinal Health and Nutrition Survey were modeled in 4 sets of analyses. Cross-sectional and multilevel models were estimated for length and weight at birth. Dynamic random-effects models were estimated for children's heights, weights, and morbidity levels during ages 2–24 mo. Children's heights and weights during ages 8–19 y were modeled by using random-effects models. Children's heights at age 22 y were modeled for investigating the effects of nutritional intakes in early childhood and in adolescence.Results: Maternal anthropometric indicators, energy intakes, and sociodemographic variables were significantly associated with children's length and weight at birth. Dynamic models for children's heights and weights during ages 2–24 mo showed significant effects of calcium and protein intakes; child morbidity levels were significantly associated with height and weight. Higher β-carotene intakes were significantly associated with lower morbidity levels. Analyses of data on children during ages 8–19 y showed significant effects of protein and calcium intakes and of morbidity levels on heights and weights. Models for children's heights at age 22 y indicated significant effects of protein and calcium intakes during early childhood and in adolescence.Conclusions: The results underscored the need for formulating long-term food and health policies for the Philippines that enhance children's physical development and ultimately their adult stature, which is important for physical work capacity and labor productivity.

Impact of pediatric inflammatory bowel disease on linear growth: Data from a national cohort study in Saudi Arabia.

Background/Aim:Linear growth impairment (LGI) is one of the most important features peculiar to children with inflammatory bowel disease (IBD). The aim of this report is to define the impact of IBD on the linear growth of children in the Kingdom of Saudi Arabia (KSA).Setting and Design:Multicenter retrospective study.Patients and Methods:Data from a cohort of newly- diagnosed children with IBD from 2003 to 2012 were analyzed retrospectively. The diagnosis of IBD was confirmed in accordance with the published criteria. Length/height for age was measured at diagnosis. The World Health Organization (WHO) reference was used and LGI was defined by length/height for age <-2 standard deviation.Results:There were 374 children from 0.33 to 16 years of age, including 119 ulcerative colitis (UC) (32%), and 255 Crohn's disease (CD) (68%) patients. The prevalence of LGI was 26%, 28%, and 21% in IBD, CD, and UC, respectively. In children below 10 years, LGI was significantly more common in CD (P = 0.010), while in UC children, it was more common in older children (P = 0.011).Conclusion:This study demonstrates a prevalence of LGI consistent with that reported in the literature, but higher in CD children with early onset (<10 years) and in older children with UC, underscoring the importance of monitoring growth in children with IBD in the Saudi population. Prospective studies are needed to define the impact of IBD on growth velocity, puberty, and final adult stature.

Effects of Growth Hormone on Bone.

Describe the effects of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) on the skeleton. The GH and IGF-1 axis has pleiotropic effects on the skeleton throughout the lifespan by influencing bone formation and resorption. GH deficiency leads to decreased bone turnover, delayed statural growth in children, low bone mass, and increased fracture risk in adults. GH replacement improves adult stature in GH deficient children, increases bone mineral density (BMD) in adults, and helps to optimize peak bone acquisition in patients, during the transition from adolescence to adulthood, who have persistent GH deficiency. Observational studies suggest that GH replacement may mitigate the excessive fracture risk associated with GH deficiency. Acromegaly, a state of GH and IGF-1 excess, is associated with increased bone turnover and decreased BMD in the lumbar spine observed in some studies, particularly in patients with hypogonadism. In addition, patients with acromegaly appear to be at an increased risk of morphometric-vertebral fractures, especially in the presence of active disease or concurrent hypogonadism. GH therapy also has beneficial effects on statural growth in several conditions characterized by GH insensitivity, including chronic renal failure, Turner syndrome, Prader-Willi syndrome, postnatal growth delay in patients with intrauterine growth retardation who do not demonstrate catchup growth, idiopathic short stature, short stature homeobox-containing (SHOX) gene mutations, and Noonan syndrome. GH and IGF-1 have important roles in skeletal physiology, and GH has an important therapeutic role in both GH deficiency and insensitivity states.

Longitudinal Increases in Knee Abduction Moments in Females during Adolescent Growth.

ABSTRACTPurposeKnee abduction moment (KAM) is an injury risk factor for anterior cruciate ligament (ACL) injury that shows divergent incidence between males and females during adolescence. The objective of this study was to determine the relation between skeletal growth and increased KAM. The hypotheses tested were that females would demonstrate peak KAM during landing at peak height velocity (PHV) and that they would diverge from males at PHV.MethodsThe subject pool consisted of 674 females and 218 males (1387 female and 376 male assessments) who participated in a preseason testing session before their basketball or soccer seasons. They were tested longitudinally for multiple years (2 ± 1 yr) to capture maturation via estimates of percent (%) adult stature and biomechanical analysis during a drop vertical jump maneuver. Data were analyzed using three-dimensional motion analysis that used a 37 retroreflective marker body model and inverse dynamics to calculate segment joint centers and peak KAM.ResultsMature females, as defined as 92% adult stature or greater, displayed increased peak KAM and knee abduction angles relative to growing (≤91% adult stature) adolescent females (P < 0.001). A significant sex–maturation (% adult stature) interaction (P < 0.001) in peak KAM was observed. Post hoc analyses showed consistent sex differences in groups greater than or equal to, but not less than, 92% adult stature, which is approximately at PHV. Hence, sex differences in peak KAM and PHV coincide.ConclusionsIncreases in peak KAM during and after PHV seem to coincide with increased risk of ACL injury in females. KAM peaked in females at PHV. Tracking longitudinal increases in peak KAM may be useful for the identification of females at increased risk of ACL injury.

Skeletal maturity of children with multiple osteochondromas: is diminished stature due to a systemic influence?

BackgroundMultiple ostechondromas (MO) is an autosomal dominant inherited disease caused by mutated exostosin genes. It mostly affects the long bones and can lead to growth disturbances, especially disproportionate short stature. Both the local effect on growth plates and the systemic influence of the gene disorder on growth mechanisms might explain the diminished stature.PurposeThe hypothesis of this study is that the diminished stature in adults with MO is due to a systemic influence, leading to early skeletal maturation and early closure of the growth plate. Therefore, in these patients the skeletal age in adolescence is hypothesized to be higher than the calendar age.MethodsRadiographs of the left hand were collected from 50 MO-affected children. The skeletal age was calculated using these radiographs according to the Greulich–Pyle bone scale and was compared to the calendar age at the time of radiography.ResultsChildren aged 3–12 years had a significantly lower skeletal age compared to their calendar age (p = 0.030). Children aged 12–17 years had a significantly higher skeletal age (p = 0.019), especially boys. Skeletal maturation in children with MO therefore differs from their peers.ConclusionIn this study, the skeletal age in younger children with MO is lower than their calendar age. For adolescents, particularly boys, this is reversed, suggesting an earlier or faster closure of the growth plates. These findings support a systemic influence of the gene defect on growth rate.

The effects of height and BMI on prostate cancer incidence and mortality: a Mendelian randomization study in 20,848 cases and 20,214 controls from the PRACTICAL consortium.

BackgroundEpidemiological studies suggest a potential role for obesity and determinants of adult stature in prostate cancer risk and mortality, but the relationships described in the literature are complex. To address uncertainty over the causal nature of previous observational findings, we investigated associations of height- and adiposity-related genetic variants with prostate cancer risk and mortality.MethodsWe conducted a case–control study based on 20,848 prostate cancers and 20,214 controls of European ancestry from 22 studies in the PRACTICAL consortium. We constructed genetic risk scores that summed each man’s number of height and BMI increasing alleles across multiple single nucleotide polymorphisms robustly associated with each phenotype from published genome-wide association studies.ResultsThe genetic risk scores explained 6.31 and 1.46 % of the variability in height and BMI, respectively. There was only weak evidence that genetic variants previously associated with increased BMI were associated with a lower prostate cancer risk (odds ratio per standard deviation increase in BMI genetic score 0.98; 95 % CI 0.96, 1.00; p = 0.07). Genetic variants associated with increased height were not associated with prostate cancer incidence (OR 0.99; 95 % CI 0.97, 1.01; p = 0.23), but were associated with an increase (OR 1.13; 95 % CI 1.08, 1.20) in prostate cancer mortality among low-grade disease (p heterogeneity, low vs. high grade <0.001). Genetic variants associated with increased BMI were associated with an increase (OR 1.08; 95 % CI 1.03, 1.14) in all-cause mortality among men with low-grade disease (p heterogeneity = 0.03).ConclusionsWe found little evidence of a substantial effect of genetically elevated height or BMI on prostate cancer risk, suggesting that previously reported observational associations may reflect common environmental determinants of height or BMI and prostate cancer risk. Genetically elevated height and BMI were associated with increased mortality (prostate cancer-specific and all-cause, respectively) in men with low-grade disease, a potentially informative but novel finding that requires replication.Electronic supplementary materialThe online version of this article (doi:10.1007/s10552-015-0654-9) contains supplementary material, which is available to authorized users.

Interpreting adult stature in industrial London.

This study examines adult stature and its association with risk of mortality in two skeletal collections from industrializing London, taking sex and socioeconomic status into account as potential sources of heterogeneity in frailty. Mean femur and tibia lengths and the distributions of short femora and tibiae were examined in adult skeletons from the cemeteries at Lower Saint Bride's (low status) and Chelsea Old Church (high status). Cox proportional hazards models were used to determine if stature was associated with risk of mortality and how that relationship varied with sex and socioeconomic status. High-status females had significantly longer femora, but not tibiae, on average, than low-status females. There were no status-based differences in mean element lengths among males. There were sex and status based differences in the distribution of short femora and tibiae, and there was a significant negative association between tibia length and risk of mortality in high-status females. The results may be explained by differences in subadult mortality, potentially due to variation in infant feeding practices. Low-status infants were more likely to live in pathogenic environments and less likely to be breastfed, leading to both stature and immunological deficits, thus minimizing the association between adult stature and mortality, as the shortest individuals did not survive into adulthood. The ways in which migration and repeated epidemics of plague may have shaped stature variation during industrialization are also discussed, highlighting the importance of context in understanding the association between stature and mortality.

Regulation of body growth.

Recent basic studies have yielded important new insights into the molecular mechanisms that regulate growth locally. Simultaneously, clinical studies have identified new molecular defects that cause growth failure and overgrowth, and genome-wide association studies have elucidated the genetic basis for normal human height variation. The Hippo pathway has emerged as one of the major mechanisms controlling organ size. In addition, an extensive genetic program has been described that allows rapid body growth in the fetus and infant but then causes growth to slow with age in multiple tissues. In human genome-wide association studies, hundreds of loci associated with adult stature have been identified; many appear to involve genes that function locally in the growth plate. Clinical genetic studies have identified a new genetic abnormality, microduplication of Xq26.3, that is responsible for growth hormone excess, and a gene, DNMT3A, in which mutations cause an overgrowth syndrome through epigenetic mechanisms. These recent advances in our understanding of somatic growth not only provide insight into childhood growth disorders but also have broader medical applications because disruption of these regulatory systems contributes to oncogenesis.

Vitamin D receptor polymorphisms and growth until adulthood after very premature birth.

The accretion of bone mass is often impaired in preterm infants, which may contribute to postnatal growth failure. We tested the effects of the vitamin D receptor single-nucleotide polymorphisms (SNPs) c1521g, Fok1, Bsm1, and Taq1 on linear growth up until adulthood in 341 subjects born very prematurely (i.e., <32weeks of gestation) from the Dutch Project On Preterm and Small-for-gestational-age infants cohort. The GG genotype of the c1521g SNP was associated with a 0.36 [95% confidence interval (CI), 0.02-0.69] SD taller adult stature and the ff genotype of the Fok1 SNP with a 0.38 SD (95% CI, 0.02-0.75) taller adult stature. Interaction between these genotypes on stature was observed from the age of 1year onward (albeit nonsignificantly before the age of 5years), with adult height being 1.54 (95% CI, 0.44-2.63) SD taller in subjects carrying both genotypes. The Bsm1 and Taq1 variants were both associated with faster catch-up growth until 2years of age. Statistical correction for potential confounders did not change our results. We conclude that homozygosity for the minor alleles of both c1521g and Fok1 is associated with a taller adult stature in subjects born very prematurely. The minor alleles of Bsm1 and Taq1 are associated with faster catch-up growth in infancy.

Association between Adult Stature and Energy Expenditure in Low-Income Women from Northeastern Brazil.

BackgroundPerinatal undernutrition may lead to important metabolic adaptations in adult life, short stature being the most visible. The present study aimed to evaluate the association between stature and total energy expenditure of low-income women.MethodWomen aged 19–45 years from low-income communities in Maceió-AL were recruited. A sample of 67 volunteers was selected and divided into either short stature (≤152.4 cm; n = 34) or non-short stature (≥158.7 cm; n = 33) group. Data on socioeconomic status, anthropometric variables, and hormonal profiles was collected. Total energy expenditure and body composition were assessed by the doubly labeled water technique with multiple points over 14 days. In addition, physical activity levels were measured with triaxial accelerometers and dietary intake data were collected using three 24-hour food records.ResultsThe mean subject age was 30.94 years. Women of short stature had lower body weight and lean body mass compared to non-short women, but there were no differences in thyroid hormone concentrations or daily energy intake between the two groups. Short-stature women showed lower total energy expenditure (P = 0.01) and a significantly higher physical activity level (P = 0.01) compared to non-short women. However, the difference in total energy expenditure was no longer significant after statistical adjustment for age, lean body mass, and triiodothyronine concentrations.ConclusionWomen with short stature present the same energy intake, but lower total energy expenditure than non-short women, even with a higher physical activity level, which suggests that they are more prone to weight gain.

Bird's-Eye View of GnRH Analog use in a Pediatric Endocrinology Referral Center

Gonadotropin-releasing hormone analogs (GnRHa) are standard of care for the treatment of central precocious puberty (CPP). GnRHa have also been prescribed in other clinical settings with the hope of increasing adult stature, although evidence to support this practice is lacking. The degree to which GnRHa are being prescribed for indications other than CPP in routine clinical care has not been described. We sought to systematically examine GnRHa prescribing practices among the pediatric endocrinologists at our academic medical center. We reviewed medical records of children treated with GnRHa during a 6-year interval. Variables analyzed included gender, age at start of treatment, indication for therapy, and use of growth hormone as adjunctive treatment. Nonparametric analyses were utilized to compare treatment characteristics of those with CPP versus those without. A total of 260 patients (82% female) aged 8.06 ± 2.68 years were identified. Of these, 191 (73.5%) were treated for CPP, whereas 69 (26.5%) were treated for normally timed puberty in the context of idiopathic short stature/poor predicted height (n = 37), growth hormone deficiency (n = 17), congenital adrenal hyperplasia (n = 10), primary hypothyroidism (n = 4), and developmental delay (n = 1). Of the 161 girls with CPP, GnRHa therapy was initiated at ≥8 years of age in 62 (39%). Whereas most patients were treated for CPP, ~27% were treated for other indications. Of girls with CPP, 39% were treated at an age when benefit in terms of height is unlikely. This highlights the need for rigorous studies of GnRHa use for indications beyond CPP.

Measuring Inequality in Living Standards with Anthropometric Indicators: The Case of Mexico 1850–1986

By analyzing the Mexican case for the period 1850–1986, we argue that the average adult stature of a population can be used as a tool to analyze inequality in living standards. The findings suggest that the secular trend in stature is related to cycles of economic growth, inequality, wars and institutional changes. Such processes affect socioeconomic groups and regions differently and generate unequal living standard patterns. Moreover, male adult average height shows a U-shaped trend for the whole period of study. As a result, Mexico lagged behind on heights with respect to other Latin American economies such as Brazil and Colombia. Two different types of data sources are used for the analysis: military and passport records for the period 1850–1950 and the 2000 Mexican National Health Survey (ENSA-2000) and the 2006 Mexican National Survey on Health and Nutrition (ENSANUT-2006) for the remaining years.

Loci associated with adult stature also affect calf birth survival in cattle.

BackgroundUnderstanding the underlying pleiotropic relationships among quantitative traits is necessary in order to predict correlated responses to artificial selection. The availability of large-scale next-generation sequence data in cattle has provided an opportunity to examine whether pleiotropy is responsible for overlapping QTL in multiple economic traits. In the present study, we examined QTL affecting cattle stillbirth, calf size, and adult stature located in the same genomic region.ResultsA genome scan using imputed whole genome sequence variants revealed one QTL with large effects on the service sire calving index (SCI), and body conformation index (BCI) at the same location (~39 Mb) on chromosome 6 in Nordic Red cattle. The targeted region was analyzed for SCI and BCI component traits. The QTL peak included LCORL and NCAPG genes, which had been reported to influence fetal growth and adult stature in several species. The QTL exhibited large effects on calf size and stature in Nordic Red cattle. Two deviant haplotypes (HAP1 and HAP2) were resolved which increased calf size at birth, and affected adult body conformation. However, the haplotypes also resulted in increased calving difficulties and calf mortality due to increased calf size at birth. Haplotype locations overlapped, however linkage disequilibrium (LD) between the sites was low, suggesting that two independent mutations were responsible for similar effects. The difference in prevalence between the two haplotypes in Nordic Red subpopulations suggested independent origins in different populations.ConclusionsResults of our study identified QTL with large effects on body conformation and service sire calving traits on chromosome 6 in cattle. We present robust evidence that variation at the LCORL and NCAPG locus affects calf size at birth and adult stature. We suggest the two deviant haplotypes within the QTL were due to two independent mutations.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-015-0202-3) contains supplementary material, which is available to authorized users.

Bioarchaeology of Neolithic Çatalhöyük: Lives and Lifestyles of an Early Farming Society in Transition

The bioarchaeological record of human remains viewed in the context of ecology, subsistence, and living circumstances provides a fundamental source for documenting and interpreting the impact of plant and animal domestication in the late Pleistocene and early to middle Holocene. For Western Asia, Catalhoyuk (7100–5950 cal BC) in central Anatolia, presents a comprehensive and contextualized setting for interpreting living circumstances in this highly dynamic period of human history. This article provides an overview of the bioarchaeology of Catalhoyuk in order to characterize patterns of life conditions at the community level, addressing the question, What were the implications of domestication and agricultural intensification, increasing sedentism, and population growth for health and lifestyle in this early farming community? This study employs demography, biogeochemistry, biodistance analysis, biomechanics, growth and development, and paleopathology in order to identify and interpret spatial and temporal patterns of health and lifestyle under circumstances of rapid population growth and aggregation and changing patterns of acquiring food and other resources. The record suggests that the rapid growth in population size was fueled by increased fertility and birthrate. Although the household was likely the focus of economic activity, our analysis suggests that individuals interred in houses were not necessarily biologically related. Predictably, the community employed resource extraction practices involving increased mobility. Although oral and skeletal indicators suggest some evidence of compromised health (e.g. elevated subadult infection, dental caries), growth and development of juveniles and adult body size and stature indicate adjustments to local circumstances.

Physical growth and ethnic inequality in New Zealand prisons, 1840–1975

The British colonization of New Zealand after 1840 was marked by an unusual concern compared to other settler colonies to incorporate the indigenous Māori population into the new society. But despite a continuing political rhetoric of protection and sovereignty, Māori have historically had lower living standards and, since the 1920s, higher rates of incarceration than European-descended New Zealanders (Pākehā). In this article, the authors examine differences between Māori and Pākehā over 130 years using prison records. Aggregate data from the Ministry of Justice shows long-term change and differences in incarceration rates. Using a data set of all extant registers of men entering New Zealand prisons, the authors show change over time in convictions and in height. The adult statures of Māori and Pākehā were similar for men born before 1900, but marked differences emerged among cohorts born during the twentieth century. By the Second World War, the gap in adult stature widened to around 3 cm, before narrowing for men born after the Second World War. Periods of divergence in stature are paralleled by divergence in fertility and indicators of family size, suggesting the possibility that increasing fertility stressed the economic situation of Māori families. The prison evidence suggests that inequalities in ‘net nutrition’ between Māori and Pākehā are long-standing but not unchanging – indeed, they increased for cohorts born in the early twentieth century. A subset of the data describing adolescents confirms that, among those born after 1945, the ethnic differential was already visible by the age of 16.

A pilot study of growth hormone administration in boys with predicted adult short stature and near-ending growth

ContextThe growth-promoting effect of starting recombinant human growth hormone (rhGH) at the time of near-ending growth has not been studied in sexually mature boys who will have idiopathic short stature (ISS) as adults because it is believed that such an advanced stage of puberty would preclude favorable results. Objectives1) To explore the effects of starting rhGH administration at time of near-ending growth in boys with ISS. 2) To search for predictors of response to rhGH. SubjectsFifteen boys aged 15.5±1years terminating puberty were growing at a rate <2cm/6months towards a predicted adult height (PAH) <−2.5 SDS. MethodsParticipants received 0.50±0.06mg/kg·wk of rhGH according to a target-to-treat protocol. When growth became less than 0.5cm in 3months or when height has reached 169cm, rhGH was ceased. Testosterone, growth velocity (GV), height, serum IGF-1, bone age (BA) at hand–wrist and knee score were measured at onset; IGF-1 and height were monitored every 3months. A formula for PAH was developed. Height increment (HI, adult height-starting height) and height gain (HG, adult height-PAH) were calculated. ResultsFollowing rhGH administration for 11.1±4.8months, GV-SDS increased from −2.5±1.7 to 3.5±4.3 (P=2×10−4), HI=8.5±3.7cm, HG=6.8±4.8cm and adult height was −1.8±0.9 SDS, compared to a PAH of −2.9±0.6 SDS (P=4×10−4). Knee score (P=2×10−3), GV at rhGH onset (P=8×10−3) and rhGH dose (P=8×10−3) were identified as predictors of HI and HG, but BA was not. ConclusionsOur study suggests that 1) a short period of rhGH administration can increase true adult height significantly in boys with ISS at time of near-ending growth; and 2) knee score rather than BA should be used to identify rhGH responders. These preliminary observations await confirmation by larger randomized trials.

Distal Renal Tubular Acidosis Presenting as Recurrent Paralytic Crises A Case Report

Abstract Renal tubular acidosis (RTA) is a syndrome resulting from tubular dysfunction leading to deranged acid-base balance. One of the subtypes, distal RTA manifests as renal parenchymal stone disease with nephrocalcinosis, evidence of vitamin D deficiency and growth faltering in children with ultimate short stature in adulthood. The physician should be familiar with the condition, in order to expedite correct management and ameliorate the complications. We hereby report a case of distal renal tubular acidosis (dRTA), who presented with recurrent hypokalemic paralysis and osteopenia but, unusually, without any nephrocalcinosis. Keywords: Distal renal tubular acidosis, paralytic crises, acid-base balance